Eibach 1200.250.0500S ERO Coilover Spring 12" x 2.5" ID 500 lb/in Silver

Vehicle Fitment

• Universal - not vehicle-specific; fits any coilover shock or suspension system that accepts a 2.50" inside diameter (64mm) coilover spring in a 12.00" (305mm) free length application
• The 2.50" ID / 12.00" length combination is used in higher-travel coilover systems across off-road racing, desert prerunner builds, rally, lifted truck performance, and road racing applications with extended-stroke shocks; at 500 lb/in, this spring rate suits a wide range of performance builds including heavier prerunner trucks, purpose-built off-road race vehicles, and competition cars requiring firm body control over a long travel range; verify your coilover's spring perch inner diameter and available shock stroke before ordering

Fitment Notes

• Inside diameter (ID): 2.50 inches (64mm) - the most broadly compatible coilover spring bore in the performance and race aftermarket; confirm your coilover's spring perch inner diameter before ordering
• Free length: 12.00 inches (305mm) - a long spring relative to typical performance street coilover kits; 12.00" is standard in high-travel coilover systems with extended shock bodies or wide perch-to-perch spacing; confirm your coilover's available compression stroke and perch-to-perch mounting distance accommodate a 12.00" free-length spring at the desired ride height and preload
• Spring rate: 500 lb/in - a high-to-moderate rate for the 12.00" x 2.50" ID ERO family; at 500 lb/in with 6.51 inches of travel, this spring handles heavier vehicle loads and more demanding dynamic conditions than the softer rates in this family (125-400 lb/in), while remaining softer than the 600 and 700 lb/in variants; suitable for coilover applications on full-size prerunner trucks, heavier purpose-built race vehicles, or setups requiring firm spring control while retaining generous travel
• Block height: 5.49 inches (139mm) - the spring coils fully solid at this height; the coilover's bump stop must engage before this point during maximum compression to protect the shock internals from bottoming damage; verify adequate bump stop clearance at full shock compression
• Maximum travel: 6.51 inches (165mm) - from free length to block; the coilover's available compression stroke must accommodate this range during normal suspension use; a 6.51" travel window on a 12.00" spring reflects Eibach's block height optimization that maximizes active stroke relative to free length
• Silver powder coat finish - the "S" suffix designates the ERO (Race Off-Road) silver finish variant; silver identifies ERO springs across Eibach's lineup, distinguishing them from the standard red ERS main springs used in circuit racing and street applications; buyers needing the red ERS finish should order the 1200.250.0500 (no "S" suffix)
• Sold individually - one spring per order; order the quantity required for your specific application

Features

• ERO (Race Off-Road) series - the ERO designation identifies this spring as part of Eibach's off-road coilover spring line, engineered for the sustained high-amplitude impacts, high-frequency cycling, and corrosive environmental exposure of desert racing, stadium off-road, and high-travel prerunner builds; ERO springs are built to the surface treatment and construction standards appropriate for off-road duty cycles that exceed what circuit racing or street use imposes
• 2.50" inside diameter - the most universally compatible coilover spring bore in the aftermarket suspension industry; fits the widest range of coilover systems from performance street kits through professional race applications; the 2.50" ID spring family is the largest single product group in Eibach's ERO catalog by number of available rates and lengths
• 500 lb/in linear rate - the rate is constant throughout the full 6.51-inch active travel stroke; a constant linear rate produces predictable spring force at every suspension position and enables precise, mathematically direct setup calculations; at 500 lb/in over 6.51 inches of travel, the spring generates up to 3,252 lbs of load before reaching block - substantial capacity for heavier performance vehicles operating over a wide dynamic load range
• 6.51 inches of active travel - the 5.49-inch block height on a 12.00" free-length spring yields 6.51 inches of working compression travel before the spring coils solid; for comparison, the 350 lb/in variant at the same length delivers 6.88 inches of travel, while the 600 lb/in delivers 6.18 inches - demonstrating the expected trend where stiffer springs require more wire and therefore reach a higher block height at the same free length, reducing available travel
• Block load of 3,252 lbs - at 500 lb/in, the spring generates 3,252 lbs (14,466 N) of compressive force when coiled solid at 5.49 inches; the coilover's bump stop must be designed to engage well before this threshold in normal operating conditions; the high block load provides a wide operating envelope between static ride height loading and bump stop engagement
• Shot-peened surface treatment - the spring wire is shot-peened before silver powder coating, introducing compressive residual stress at the wire surface that closes fatigue micro-cracks and dramatically extends service life under the repeated high-amplitude impacts and high-cycle loading of off-road and race environments
• Preset to block - every Eibach ERO spring is factory-compressed to block before shipment; this eliminates the initial sag that occurs during a new spring's first compression cycles and ensures the rated 12.00" free length and 500 lb/in rate are delivered immediately upon installation with no break-in period required
• Individually rate-tested - each spring is measured against its rated 500 lb/in value on Eibach's rate testing equipment before leaving the factory; consistent rate is guaranteed spring-to-spring, ensuring the installed spring matches the specification on the suspension engineer's setup sheet
• Silver powder coat finish with imprinted part number - the ERO silver finish provides corrosion resistance against mud, water, dust, and debris in off-road and prerunner environments; the spring rate and part number are stamped directly on the spring body for correct identification after packaging is removed or springs are mixed in a shop inventory

Specifications

• Part Number: 1200.250.0500S
• Manufacturer: Eibach
• Series: ERO (Eibach Race Off-Road)
• Spring Type: Main coilover spring, linear rate
• Free Length: 12.00 inches (305mm)
• Inside Diameter (ID): 2.50 inches (64mm)
• Spring Rate: 500 lb/in (8.94 kg/mm)
• Block Height: 5.49 inches (139mm)
• Maximum Travel: 6.51 inches (165mm)
• Block Load: 3,252 lbs (14,466 N)
• Weight: 6.06 lbs (2.75 kg)
• Finish: Silver powder coat
• Surface Treatment: Shot-peened
• Preset: Yes - factory preset to block
• Quantity: Sold individually (1 spring)

Included Components

• 1x Eibach ERO Race Off-Road Coilover Spring - 12.00" x 2.50" ID x 500 lb/in (silver)

Product Description

The Eibach 1200.250.0500S is a single ERO (Race Off-Road) series coilover spring - the 12.00-inch free length, 2.50-inch inside diameter, 500 lb/in linear-rate variant from Eibach's off-road coilover spring lineup. The "S" suffix designates the silver powder coat finish that identifies all ERO series springs across Eibach's catalog, distinguishing them from the standard red ERS main springs used in circuit racing and street performance applications.

At 12.00 inches of free length and a 5.49-inch block height, this spring delivers 6.51 inches of active compression travel - a generous stroke that positions this spring in the same high-travel applications as the 350 lb/in variant (6.88" travel) and 600 lb/in variant (6.18" travel) in this same 12.00" x 2.50" family, while hitting a useful midpoint in the rate and travel range. At 500 lb/in generating a 3,252-lb block load, this spring is appropriate for full-size prerunner trucks, heavier purpose-built off-road race vehicles, and performance suspension setups requiring firm body control over a long stroke. The 2.50-inch inside diameter ensures compatibility with the broadest range of coilover systems in the off-road and prerunner market.

Shot peening, factory preset-to-block treatment, and individual rate testing are standard across every ERO spring. The spring rate and dimensions are stamped on the silver powder-coated body for shop identification. Sold individually.